Cabin pressure regulator valve



Oct'. 12, 1948. H. cRUzAN CABIN PRESSURE REGULATOR VALVE Filedl July 12, 1944 INVENTOR. HAROLD CRUZAN ATTORNEY Patented Oct. 12, 1948 My invention`v relates' to means'for' ymaintain-- ingv and controllingfair' pressure' in "the 'cabins' of aircraft' during "flight, and relates 'in"particula'1 to the -s'imple outlet' 'valve device for regulating the internal cabin pressure Within'spacedvlimits' and in accordance` with a predetermined value.y

Control of air pressure'within' thev 'cabins of, aircraft is now'accomplished byuse or relative-` lyconiplicated pressure sensitive devices Which control outlet'valves so that during the iiight'of aircraft pressure above the ambient flight pressure will be main-tained vWithin the cabins. It is an object of" my invention to provide a simpl/e valve' device which may in'rnany instances replace the complicated 'and expensive mechanisms" referred to in the foregoing.

It is an'object of the invention to provide-an outlet valve adapted to 'be mounted onthe 'eX- terior of 'a pressurized portion of -a cabin or'in a bell or depression which projects into the ycabin space, which will control the outflow of `air from` the cabin so as to maintain Within the cabin pressure conditionsl which are Within 'the-specifications established by the United States Army. For example-,this simple and inexpensive valvede vice may have its-cooperating parts sorelated that between'sea level and an altitude ofA aboutV 8000 feet, the cabin pressure will correspond vto ambient flight pressure, Within `relatively close limit-s of deviation, and which will. main'tain'the cabin pressure isobaric'until the aircraft reachesY an ambient flight pressure-corresponding t lan altitude of about 25,000 feet,andwhichiwill thereafter maintaina idifferential pressure between the cabin -in'terior and the arribient,.flightlpressure existing outsidewthe aircraft cabin.

It is anobject -offthe invention to provide an outlet valve for a pressurized cabin which Controls the oW'lof airA Afrom the cabin so` as to maintain prescribed pressure Yconditions inv-the cabin .and

which incorporates means fo'r release of, excess pressure from the cabin soA 'that-such excess-pres'- sure willnot exceed ya prescribed-value' and therefore -Willnot endanger'l thev cabin' structure.:

It;` is' a durtherfnbjecti ofthe. inventiomto rprovide an Aoutlet :valve device for". a 'pressurized cabin; having an; air. outlet .port' for.' (connecting,

the interior of the'cabinrwith theexterior, and a valve vdisposcdrin externalirelation to the :port liaViiigpreSSure 'sensitive' means of simple character to automaticallyimove A'the/valve in ward jtoward f 'the :port zas; the.. aircraft ascends from a.relatively'iow'flevel+for example, near sea reeel-through variouszhigher altitudes Within range otflight of' tlienaircraft, .thexzvalv'e :device being "characterizedcby an ability to 'maintain prescribed pressure conditions `Within 4the pres'- sui-izedy cabinrwithout"'themeed" for 'any' internal' or complicatedpressurer sensitive' mechanism.' i

Aiurther'objeet of the invention `:is to provide a valve of thisI character'which is' adjustablel'for' simple'f'outlet4 valve Afor' pressurized" cabins;A have' ing-'an air'outlet" port and'a'valve'rnovably dis:v posed in' external relation: to' 'the' port; thatis' to. say-' thevalve'cooperates With'the' pai-tof' the' port which facesftoward'-the' external'atrnosphere' instead of that portion of the portwhic'h 'races' the cabin interiorthis control'-` valve" device hav-ing 'in la position` outside; the' 'cabina 'control' in'this'outlet valve"devicega'cooperation'of parte which 'will l per-miti' outward`-A movement of the" Val-ve With rel-ation* to thefjair-outlet'-port :when: the pressure diierential- :between- 'the' interiorv and-1.. exterior 'of'- the-'cabin rises above 1 a "prede-f terminedvvalue Furthen'objects andadvantages of the-inven-- tion f will fbe': broughtVv -ou-t` -in'l the following "part of'. the. Lspecication.'A

Referring to" the .drawing Whiehfislfor illustrae tive ipurposes only',

which:thefinventionfmay 'beeconnected to'a pressurized caircraft: cabin".

Fig.-y 2 lis-ran enlargedsectional-Niew of 'a pre-'- ferredf'embodiment vofiny outlet val-ve device'.-

Figict's is a partly sectionedview','- showing thepartsxof the: fdevic'e: :in i the positions'. which 'they' continuouslyfiedby somegsuitablemeans such ras a :blower ILS For .the A"escape oflfairy from' the'- cabin 'nl 0 Lso :that =a srcontinuous circulation-gef fairf;

orma "continuous replacement'fof `4 vair rrray Abe tobi' mounted on the wall I4 of the cabin so as to communicate through the openings I2 and I3 with the interior space of the cabin. It will be understood that one or more of these valve devices I5 may be employed and that they may be disposed so as to produce a desired circulation of air through the cabin, whereby stagnant zones will be avoided.

In Fig-s. Z and 4 I show details of construction of a preferred form of my simple valve device. It includes a frame or support I6 having an annular wall I1 which may be connected to the wall I4 of the cabin I0, this wall I1 having a threaded opening I8 to receive an annular wall member I9 which has therein an air outlet opening or port 250, and which is externally threaded so that by rotation it may be caused to move outwar-d or inward. in the threaded opening I8 of the support I6. That portion of the annular wall I9 which defines the port 20 is rounded or flared as indicated at 2|. The support I6 has a plurality of arms 22, for example-six-projecting outwardv therefrom in spaced arrangement around the projected axis of the port 28, and a supporting wall 23 is connected to the outer ends of these arms '22 by means of screws 24.

The member 23 has a threaded opening 25 axially aligned with the port 2U, this threaded opening 25 receiving a threaded bushing 26 which may be adjusted inward or outward as may be required in adjustment of the valve device and then locked by means of a lock nut 21. A bar or stem 28 is slidable in the opening of the bushing 26 and has adjustable means 29 such as lock nuts thereon for limiting the inward movement of the stem 28.

The stem 28 has on its inner end a base 30 comprising a circular plate having in its peripheral portion projections 3I slidable between the bars 22. This base 30 is adjustable toward and away from the port 20L A compression spring 32 is disposed so that one of Vits ends will engage the upper or back face of the base 3Il,`

and so that its other end will engage an adjustable spring compressor plate 33 which is secured to the lower end of the bushing '26. This spring 32, the pressure of which may be varied by adjusting the bushing 26 through the threaded opening 25, urges the base 30 toward the port 20 and into a position which is determined by the setting of the stop 29 on the stem 28. It will be perceived accordingly that the position of the base "30 may be varied merely by adjusting the stop 29 and that the base 30 will yield upwardly or outwardly under a pressure which is determined by the adjustment of the spring 32.

On the lower or inner face of the base 3U there is a collapsible chamber member consisting of a metal bellows 35, one end of which is connected to an annular flange 3B formed on the base 30 and the other end of which is connected to a circular plate or wall 31 which has a threaded axial projection 38 equipped with an opening 39 to which an evacuating tube 40 is connected. When this collapsible member, represented by the bellows 35, and its associated part is evacuated, external air pressure forces the plateg31 kagainst' a stop 4I consistingof a projection from the base 30.

A valve 42 is provided for externalcooperation with the port ,20, thisvalve -consisting ofY aV convexly rounded wall, having'at the periphery thereof the radial annular. wall 43 which joins a cylindric wall 44 so that a cup is formed from` the walls v42, 43, and 44 which substantially sur- 4 rounds the bellows 35. Flanges 45 project from the upper margin of the cylindric wall 44 and extend into the spaces between thebars 22. The valve 42 has on its outer face an internally threaded projection 41, whereby it may be connected to the wall 31 ofthe evacuated capsule comprising the bellows 35, so that the valve 52 and the wall 31 act as a single part. A compression spring 48 is disposed inside the cylindric wall 44 and between the base 30 and the annular wall 43 associated with the valve 42, to exert a force urging the valve 42 toward the port 20. The valve device also includes means for limiting the movement of the valve 42 relatively to the base 30 so that by this adjustment, the movement of the valve 42 toward the port 20 may be governed. This means of adjustment consists of screw members 49 which are extended through openings 510 in the flanges 45 and aligned openings 5I in the base 30. When the 'screws 49 are screwed in place in the plate 30, they become an integral part of the member 30 with the projected end portion carrying the lock nut 52. The effective lengths of these screws 49 may be varied by screwing them inward or outward. Y

It is to be understood, of course, that the valve 42 is always open, at least to some extent, so that the cabin will be ventilated at all times, air under f been found that superior results are obtained byV convexly contouring the seatingsuriace oi said valve and although said seating surface is convex, the effective area of the outlet valve port is substantially equal to the effective cross sectional area of the aneroid or bellows 35.

pressure `is maintained at substantially a constantY level' as shown at 55' in the chart of Fig. 5.

In Fig. 2 the outlet Valve device is shown with its cooperating parts in the positions which they assume when the device is at sea level. The base 3U has been adjusted to a position wherein the valve 42 will be spaced from the port 20 a distance determined in accordance with the conditions of operation prescribed for the device, such conditions including rate of flow of air through the port 25 and pressures which are to be maintained at diierent times within the cabin. The spring 32 is set by adjustment of the bushings 26 so that the base 30 and the valve 42 will yield upward or outward in response to a predetermined pressure differential applied to the Vface of the valve 42 and transmitted to the base 30.

toward the port 2i) to restrictv the flow of'rair outi ward through the port 28. .t will be perceived that'Vv the valve 42 is exposed to pressure of air which is owing outward through the port 2] and that when the valve 42 Vis moved into a position such as that at which it is shown in Fig. 3, by expansion of the bellows 35, the valve 42 will be exposed to The amount This is neces'-- sary in order to obtain the desired control of cabin pressure in therisobaric range, which cabin the pressure of airf within the cabin,.through the port 20.. The spring 48 isso calibrated nthat-the valve 42 will not start to close until a desired altitude has been reached. For example, as shown bythe curve of cabinpressure 55=ofthe graph, Fig. 5, cabin pressure will follow ambient ight pressureEG until an altitude of about 80GO-feet is reached. Then,the closing of the Valve 421.*by the aneroid means associated therewith will cause the curve to level off as indicated'at 55 asfthe. result of a -restriction of outow-ofwair through the valve 28 -in such a manner as tomaintain :the pressure of air Within-the cabin .substantially constant until an altitudeofv approximatelyBOOOO feet is. reached byy the aircraft. At-this time the cabinpressure 4differential exerted-against ythe valve 42 'exposed in the port -20v will besuch-fas tofovercomethe force of -the -spring 532 so' that the base 30 and the part,'support-ed-therebyiwill move upward or-outwardas further expansion of the bellows 35- occurs, thereby' maintainingy lthe valve opening- SyFig. 3, at such area with relation tothe rate of now of air into the lcabinandi the pressure differentialexisting between `the interior and the exterior of the cabin tha-t the cabin pressure will drop-off as indicated by the portion- 55a of the'curve 55, tti-thereaftermaintain-substantially Vconstant pressure diierential between the'interiorand exterior of the cabin.'

Frolrn-the vforegoing explanation,'and :from Vthe graph, v IE'ig. 5, it will be :noted that jthissimple control valve maintains withinthe cabina presi-1 sure `which follows ambientxight; pressure until a prescribed altitude is;-reached;and-thenfmainf tains pressure within the cabin while ambient night Vpressure dropswith increase .in;.altitude; and then :when a predetermined-diiierential pres:- sure between the cabin-andambientxflightpresf sure isi-reached,l controls the outflowfof air romthe cabin, through the valve port 25Min a manner to produce a drop in the cabin pressure which:cor'l responds to the drop irl-ambient.ightpressure, thereby, preventing the air pressure withinithe cabinhfrom exceeding a prescrib'ed'diflz'erential' from' ambient flight pressure.Y

In :the setting ,of the valve device, the `rate/of flow of air is. taken into consideration andias par-t of, 'the adjustment; the. porteformingz'ring l'is'adjusted inward or outward withfrelation tothe valve y12. The characteristics:of` the. valveV do not change greatly when the device is adjusted for dilerent rates of Iflow. The curve 55'in Fig. 5 is a graph of-cabin pressure maintained fby :the valvel with a flow of Yve pounds per-minuteA of airt through the valve port. Where the rate oiairfiow is increased, the cabin pressure Ywilliiollow .the valuesindicated'by the curve B5 and. .Where the flow Yis'decreased, cabin pressure will follow -the curve 86".-Y

Adjustment of the screws 49 inward orfoutward will determine the :expansionfof the. bellows .35 when the' device is operatinglon diferentiah.A

I claim" asr my invention 1. In f a system for controlling and :maintaining pressure withina cabin having :meansror'de'liverirrg. a flow of air under pressure'into'said-cabin, an outlet valve means for 'controlling -the flow of air fromfl the cabin, comprising: a support adapted tobefconnecte'dto the cabin wall; awal1 carriedxby lsaid support fdening anroutlet vportconnecting -the interior'of said cabinz -withftheexterior thereof;' a-valve"disposed outside* 'said port vso as Sto-be fm'oveditoward andlawayfrom the portg'said-valve having an zinner'A face y'exposed through-said port-to pressureof' air derived-from theinterioroffsaid cabin; abase supportedby said support ina position spaced voutwardy from 'said valve-and so as to have movement toward and awayfrom said-port; an adjustable stop for limiting'the movement of said base toward said port; adjustable Aspring means for urging said base towardY said stop; and .atcontrol element lcomprising 4an evacuated collapsible chamber member exposed to atmospheric pressure and connected at one: end '.to said base and at the other end to said valve so that expansion-of -said collapsible member- Will-move said valve toward-1 said port; said control elementalso incorporating spring means acting between said base and said valve to urge said vvalve toward saidv port.

2. In `a system for-controlling and maintaining pressure within a cabin having means` for delivering a owfof air under pressure into said cabin, anf outlet'valvemeans for controlling the-110W of air' from the cabin,v comprising: a support adapted't-o be connected `to the cabin wall; a Wall carried bysaid'support defining an outlet port connectingxthe interior of said cabin with the exteriorA thereof; a-valve disposed 'outside said port so as tov be moved toward andiaway from the port; said' valve having `an innerface exposed throughisaidport'to pressure of air derived from tliexinterior of'said cabin; a base 'supported Yby sajd'fsupport in a position spaced outwardxfrom said fvalve and so as to have `movement toward andza'away/ffroml said port; means for limiting movement' of said valve relatively to said base;r an adjustable stopfor limiting the movementrof saidbase `toward said port; adjustable Aspring means-.for urging said base toward said stop; and afcontrolelementcomprising an evacuatedcol'- lapsibl'e chamber member exposed to atmospheric pressure and connected at one end to 'said base and' at the other end to said valve so 'that eX- pansion'of said collapsible member will move said valvey toward said port, said control element also comprising f spring means to urge said valve toward said port.

3. In a system for controlling and lmaintaining pressurewithin a cabin having means for deliveringfa flowof air under pressure into saidcabin, an :outlet valve means for controlling the flow of ai-r from'the cabin, comprising: a support adapted tobeconnected to the cabin wall; a wall carried by said support dening an outlet port connecting the interior of -said cabin with the exterior thereof;' a v-valve disposed outside said port so as to be moved toward and away from the port, said valve having'faninner face exposed through said port to pressureof air derived from the interior vof saidy cabin; a base supported by said support in a positionspaced outward from said valve and so asl to havemovement toward and away from said port; means for limiting movementof said valve relatively `to said base; an adjustable stop .for limitingthe movement of said base `toward said port;l adjustable spring means for urging vsaid baseeto'ward said stop; a control element comprisingfan evacuated collapsible chamber mem- 'berl'exposedfto atmospheric pressure'and connectedA atome end to said'b-ase and at the other endto said valve so that expansion of said collapsible member will move said valve toward said port,l said control element also comprising spring means to vurge said valve toward said port; and means -for-adjusting-said port-defining wall in said'support towardv and away from said valve.

4,'In'a system for controlling and maintaining pressure within a -cabinhaving means for deliverirg 'a wfof'air under pressure into said cabin;v

and outlet valve means for controlling the flow of air from the cabin, comprising: means forming an outlet valve port connecting the cabin interior with the exterior; a valve in movable relation to said port, the inner face of said valve being exposed to pressure of air derived from the interior of said cabin through said port; and pressure responsive means outside said cabin connected to the outer portion 'of said valve comprising an aneroid element subjected to atmospheric pressure and having a base and a movable part, said movable part being connected to said valve so as to move said valve inward toward said port as said aneroid element expands, and yieldable means for supporting said base in spaced relation to said valve port so that said valve may move automatically in va direction to permit an increased flow of air through said port when the pressure existing in said port, acting on the adjacent face of said valve, exceeds the force of said yieldable means transmitted to the other side of said valve through the aneroid.

5. In a system for controlling and maintaining pressure within a cabin having means for delivering a flow of air under pressure to said cabin: outlet valve means for controlling the flow of air from the cabin, said means comprising means forming an outlet valve port connecting the cabin interior with the exterior; a valve member in movable relation to said port externally thereof; pressure responsive means connected to said Valve and disposed externally of said cabin and responding to variations in pressure of the air outside of said cabin for varying the position of said Valve relative to said port as the pressure of air outside said cabin varies; guide means for the pressure responsive means and valve whereby said means and valve may move toward and away from the port; and yieldable means urging said pressure responsive means and valve toward said port and yielding to enable automatic outward movement of said valve when the differential of pressure between the interior and exterior of said cabin reaches a predetermined value.

6. In mechanism for controlling and maintaining pressure within a cabin having an outlet port for connecting the cabin interior with the exterior: a valve member in movable relation to said port externally thereof; yielding means urging the valve toward closed position and yielding to permit the valve to open under pressure of air on the port side thereof; and pressure responsive means directly connected to said valve member independently of said yielding means and disposed externally of said cabin and responding to variations in pressure of the air outside of said cabin for varying the position of said valve relative to said port as the pressure of air outside said cabin varies.

'1. In a system for controlling and maintaining pressure within a cabin having means for delivering a now of air under pressure thereinto: means forming an outlet valve port connecting the cabin interior with the exterior; a valve in movable relation to said port, the inner face of said valve being convexly contoured'and exposed to the pressure of air in said cabinlthrough said port; yielding means urging the valve in the closing direction and yielding to permit the valve to open when the differential of pressures on opposi-te Ysides of said valve reaches a predetermined value; and pressure responsive means outside said cabin and directly connected to said Valve independently of said yielding means, said pressure responsive means comprising anvpaneroid element,

8 the crosssectional areaof said aneroid element being substantially equal to the area of said outlet valve port. Y

`8. In a system for controlling and maintaining pressure within a cabin having means for deliv- Y ering a flow of air under pressure into said cabin: a support adapted 'to be connected to the cabin wall; a wall carried by said support dening an outlet port connecting the interior of the cabin with the exterior thereof; a valve disposedv outside said port so as to be moved toward and away from the port, said Vvalve having an inner face exposed through said port to presM sure of air derivedfrom the interior of said cabin; a movable base supported by said sup port in a position spaced outwardly of said valve; means for limiting the movement of said valve relative to sai-d base; a control' element comprising collapsible wall means having one end secured to said base and having the'opposite end connected to said valve and defining an evacuated collapsible chamber of substantially the same diameter as said port, said control element, upon expansion thereof, being adapted to move said valve toward said port; a spring urging said valve toward said port; and yielding means for urging said :base and valve toward said port.

9. In a system for controlling and maintaining pressure Within a cabin having means for deliv` ering a -ow of air under pressure into said cabin: outlet valve means for controlling the ow of air from the cabin and including a support adapted to be connected to the cabin wall; a wall carried by said support and defining an outlet port connecting the interior of said cabin with the exterior thereof; a valve disposed at the outer side of said port so as to be moved toward and away therefrom, said valve having an inner face 'exposed, through said port, to air pressure derived from the interior` of said cabin; a pressure responsive 'control element having a base movably supported on said support in a position spaced outwardly of said valve, a collapsible wall con-I nected at one end to said base and having its valve toward said port, the effective cross sectional area of said control element being substantially the same as the area of said port; and yielding means acting on said base for urgin the base and valve toward the port,

l0. In an outlet valve for controlling and maintaining pressure within an aircraft cabin having means for delivering a ow of air under pressure into said cabin: means forming-an outlet port adapted to connect the cabin interior with the exterior; a valve in movable relation to the external side of said port; pressure responsive means including a movable wall connected to said valve, means supporting said pressure re1- sponsive means for movement toward andV away Y means urging thersupport for said pressure responsive means toward theV valve port Vand yielding in a valve opening directionrwhen the diiferential pressure betweenthe interior and exterior of said cabin reaches a predetermined value.

171. In a system for controlling and maintain# ing pressure within a cabin having means for delivering a flow of air under pressure into said cabin; means forming an outlet valve port connecting the cabin interior with the exterior; a valve in movable relation to said port externally thereof; pressure responsive means attached to said valve and defining an evacuated space ydisposed externally of the cabin, one face of said valve being exposed to the pressure of air in said port over an area substantially equal to the effective area of said pressure responsive means, said pressure responsive means controlling the position of said valve relative to the position o'f said port as the pressure of air outside of said cabin decreases and increases; resilient means urging the valve in a direction opposed to the pressure of air in said port; means for supporting the pressure responsive means and valve for movement toward and away from said port; and yieldable means urging said supporting means, pressure responsive means and valve toward said port and yielding when the diierential of pressure between the interior and exterior of the cabin, as exerted on said valve, reaches a predetermined value.

12. In a system for controlling and maintaining pressure in a cabin having means for delivering the flow of air under pressure into said cabin, comprising: outlet valve means for controlling the flow of air from said cabin, including a wall which defines an air outlet port connecting the cabin interior with the exterior: a vavle in movable relation to said port externally thereof, one face of said valve being exposed to the pressure of air in said port; means for adjusting said wall with respect to said valve; pressure responsive means disposed externally of the cabin and connected to the valve; resilient means urging the valve in a direction opposed to the direction of pressure on said valve exerted through the port, said pressure responsive means controlling the movement of the valve toward and away from the port as the pressure of air outside the cabin decreases and increases; a support for the pressure responsive means and valve whereby said means and valve may move as a unit toward and away from the port; and yieldable means urging the support, pressure responsive means and valve toward the port and yielding to permit opening of the valve when the differential of pressure between the interior and ex- 10 terior of the cabin reaches a predetermined value.

13. In a system for controlling andmaintaining pressure Within a cabin having means for delivering a flow of air under pressure into said cabin: outlet Valve means for controlling the ow of air from the cabin, said means having an outlet valve port connecting the cabin interior with the exterior; a valve in movable relation to said port externally thereof and having one face exposed to the pressure of air in said port for urging said valve in the opening direction; pressure responsive means outside of said cabin comprising an aneroid element having a base and a movable wall connected to the valve s0 as to move said valve toward said port as said aneroid element expands; a support, said valve and aneroid being movably supported by said support; resilient means urging the valve in a direction opposed to the pressure of air in said port; a yielding means exerting pressure on the base of the aneroid for urging the aneroid and valve toward said port and permitting outward movement of the valve when the differential of pressure between the pressure in said port and the exterior of said cabin reaches a predetermined value.

HAROLD CRUZAN REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,562,663 Strong Nov, 24, 1925 2,002,057 Gregg May 21, 1935 2,160,453 Boles May 30, 1939 2,208,554 Price July 16, 1940 2,258,054 Heidbrink Oct. '7, 1941 2,316,416 Gregg Apr. 13, 1943 FOREIGN PATENTS Number Country Date 4,453 Australia l Oct. 28, 1926 679,386 France Jan. 9, 1930 OTHER REFERENCES Pressurized Cabin Control, by Tinker et al. Aviationf January 1941 issue, pages 38, 119J 124. Copy in Div. 49. 

